From the referenced post it seems that the reason you no longer support embedded is that it's unsafe for production. It's a common use case to want to unit / integration test ES code outside of a production environment; many of your clients currently do this. This is similar to in memory relational database testing, which can also be useful.
May I suggest that you consider providing some kind of support for embedded testing in a future release. This will be impacting my choice as I decide which search tool our company will use going forward, as will the quality and tone of responses I receive here.
Regards
Kieran